feat(extractor): implement multi-engine article content extractor

- Added scripts/extract_article_contents.py for batch scraping with stealth Foxcape and triple extraction (Trafilatura, Newspaper4k, Readability)
- Created unit, integration, and E2E test suite in tests/test_extract_article_contents.py (90/90 passing)
- Updated specs/003-article-content-extractor and README.md with usage documentation and CLI contracts
- Passed ruff linting/formatting and mypy type checking cleanly

classify.py

@@ -4,13 +4,12 @@
 from __future__ import annotations
 
 import argparse
-import json
 import sys
 from pathlib import Path
 
 from src import __version__
-from src.models import ECPSnapshot, ClassificationError, ErrorCode
 from src.classifier import InherenceClassifier
+from src.models import ClassificationError, ECPSnapshot, ErrorCode
 
 # Ensure UTF-8 output streams across all platforms
 if hasattr(sys.stdout, "reconfigure"):